Roller piston type rotary engine

ABSTRACT

A large volume cylinder and a smaller volume cylinder are separated by a bulkhead. Extending through both cylinders is a crank shaft. Loosely mounted on the crank shaft are a larger roller piston within the large cylinder and a smaller roller piston within the smaller cylinder. The roller pistons are mounted eccentrically approximately 180* out of phase with each other. Slide plates are urged into each of the cylinders to tightly contact the outer walls of the pistons. A gap is provided between the lines of contact of the slide plates with their respective pistons. A hole communicating between the cylinders extends through the bulkhead in the area of the gap. A suction hole extends into the large cylinder on the side of the respective slide plate opposite the communicating hole, and an exhaust hole extends into the smaller cylinder on the side of the respective slide plate opposite the communicating hole.

O United States Patent [15] 3,

Nakamura 1 Aug. 8, 1972 ROLLER PISTON TYPE ROTARY FOREIGN PATENTS OR APPLICATIONS ENGINE 11,548 4/1905 Great Britain ..l23/8.41

[72] Inventor: Eishin Nakamura, 426 Nagoya,

Hidaka-Mura, l-lata-gun, Kochi-ken, Primary Examiner-Carlton Croyle Japan Assistant ExaminerJohn J. Vrablik Filed: g 1970 Attorney-Wenderoth, Lind & Ponack [21] Appl. No.: 63,486 [57] ABSTRACT A large volume cylinder and a smaller volume cylinder [52] US. Cl ..418/11 are separated by a bulkhead. Extending through both [51] Int. Cl ..F0lc l/30, FOlc 11/00, F03c 3/00 cylinders is a crank shaft. Loosely mounted on the [58] Field of Search ..418/1 1, 12, 60; l23/8.l5, 8.23, crank shaft are a larger roller piston within the large 12 41 cylinder and a smaller roller piston within the smaller cylinder. The roller pistons are mounted eccentrically [56] e e c Cited approximately 180 out of phase with each other. Slide plates are urged into each of the cylinders to UNITED STATES PATENTS tightly contact the outer walls of the pistons. A gap is 711,092 10/1902 Bates ..418/11 provided between the lines of contact of the slide 1,440,451 I/ 1923 Ford ..l23/8.l5 plates with their respective pistons. A hole commu- 3,023,742 1962 Udelman nicating between the cylinders extends through the 3,191,403 6/1965 Ladusaw ..418/60 bulkhead in the .area of the gap. A suction hole exl,275,619 8/1918 Smiley ..l23/8.l5 tends into the large cylinder on the ide of the respee 1,730,443 1/ 9 sqhumann tive slide plate opposite the communicating hole, and Kinney an exhaust hole extends into the smaller cylinder on 2,284,1 Warner the side of the respective lide plate opposite the communicating hole.

4 Claims, 7 Drawing Figures k 5 5 6 w A i l 5 s. g j 57 i I j w 1 3 La f E 2' ,i ll l2 9 8 /l E Y 4 i AR 1 f i. I 0 D W 3t Y' Y 3 t \1 PATENTEUI B 8 I972 sum 2 or 2 INVENTOR EI 51-11 N NAKAMURA ROLLER PISTON TYPE ROTARY ENGINE BACKGROUND OF THE INVENTION The present invention relates to an improved roller piston type rotary engine. More particularly, the present invention relates to such an engine employing the use of two roller pistons having different volumes and eccentrically mounted approximately 180 from each other on a crank shaft.

Heretofore, many rotary type engines have been well-known. These prior art engines have employed the use of two roller pistons having identical volumes. However, these engines have suffered from certain inherent defects. Specifically, such engines have required a complicated structure employing the use of three separate chambers. In these prior art engines, fuel is induced into a compression chamber and compressed. Fuel is then supplied to a combustion chamber where it is ignited by an electric plug. Lastly, the exploded combustion gas is supplied to an operating chamber wherein rotation is imparted to the engine. Manifestly, such an engine must be constructed with a high degree of precision to insure proper operation in timing of this three stroke operation.

With these disadvantages in mind, it is a primary object of the present invention to provide a rotary type engine in which the above disadvantages are eliminated.

It is a further object of the present invention to provide a rotary engine employing a relatively large chamber and a large roller piston mounted therein for performing the operations of suction and compression, and a second relatively smaller chamber and a smaller roller piston mounted therein for performing the operations of combustion and rotation of the engine.

It is a further object of the present invention to provide such a rotary engine wherein the operations of suction, compression and exhaust are permitted by the operation of slide plates adapted to open and close engine ports by their sliding contact with the roller pistons.

It is a yet further object of the present invention to provide such a rotary engine wherein these operations are performed alternately by the eccentric rotation of the roller pistons which are mounted out of phase with each other by approximately 180 on a single crank shaft.

It is even a still further object of the present invention to provide such a rotary engine wherein the outer walls of the roller pistons which abut the inner walls of the engine chambers constantly shift, whereby the friction acting on the roller pistons is reduced.

These objects are achieved in accordance with the present invention by the provision of a rotary engine having therein two separate cylinders of different volumes and separated by a bulkhead. A single crank shaft is adapted to rotate and extend transversely through the two cylinders. Mounted eccentrically and loosely around the crank shaft in the larger of the two cylinders is a relatively large roller piston. Mounted eccentrically and loosely on the crank shaft in the smaller cylinder is a relatively smaller roller piston. The two pistons are mounted out of phase with each other by approximately 180 Mounted on the exterior of the rotary engine are two air tight chambers the planes of which are parallel with the axis of the crank shaft. The

first of these air tight chambers communicates with the larger cylinder and has a first slide plate extending therefrom into the larger cylinder and abutting the outer wall of the larger roller piston. Springs are positioned in the air tight chamber to urge the first slide plate into tight'contact with the outer wall of the larger roller piston. The second air tight chamber is in communication with the smaller cylinder and has therein a second slide plate extending therefrom into the smaller cylinder and in contact with the outer wall of the smaller roller piston. Springs are positioned to urge the second slide plate into tight contact with the outer wall of the smaller roller piston. A hole is provided between the two cylinders through the bulkhead. A suction hole extends through one side wall of the rotary engine and into the larger cylinder. An exhaust hole extends through the opposite wall of the rotary engine and is in communication with the smaller cylinder.

Other features of the invention will be made clear by the following description, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross sectional view of a rotary engine in accordance with the present invention;

FIG. 2 is a side elevational view from the right in FIG. 1 with a portion broken away;

FIG. 3 is a cross sectional plan view of the rotary engine in accordance with the present invention;

FIG. 4 are simplified schematic views of a rotary engine in accordance with the present invention illustrating various operating positions thereof;

FIG. 5 is a perspective view of the lower end of one of the slide plates in accordance with the present invention;

FIG. 6 is a simplified cross sectional illustration of parts of the rotary engine in accordance with the present invention; and

FIG. 7 illustrates cross sectional views taken along line I-II of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION The rotary engine of the present invention includes a relatively large volume cylinder 2 and a relatively small volume cylinder 2' separated by a bulkhead 1. Journalled to transversely extend through and rotate in cylinders 2 and 2' is crank shaft 4. Eccentrically mounted on crank shaft 4 in the small volume cylinder 2' through center groove 3a is a relatively small volume roller piston 3'. Pistons 3 and 3' are mounted out of phase with each other by approximately by means of conventional bent portions on the crank shaft. Piston 3 has center cylindrical cavities Y formed therein to accommodate crank shaft 4, and piston 3' has center cylindrical cavity Y formed therein to accommodate crank shaft 4.

Mounted above and in communication with cylinder 2 is a first longitudinal air tight chamber 6 which extends radially in the direction of crank shaft 4. Within chamber 6 is positioned a first slide plate 5 which extends into cylinder 2 and abuts the outer wall of piston 3. A spring 4 is positioned in chamber 6 to urge slide plate 5 into tight contact with the outer wall of piston 3. Mounted above and in communication with cylinder 2 is a second longitudinal air tight chamber 6' which extends radially in the direction of crank shaft 4. Mounted within chamber 6 is a second slide plate which extends into cylinder 2 and contacts the outer wall of piston 3'. A spring 4" is positioned in chamber 6' to urge slide plate 5 into tight contact with the outer wall of piston 3. It will be apparent that as pistons 3 and 3 rotate within cylinders 2 and 2' respectively, slide plates 5 and 5 respectively, are alternately urged up and down against and by the force of springs 4' and 4", respectively. Chambers 6 and 6' are arranged such that a slight gap 7 (see FIG. 3) exists between the line of contact between slide plate 5 and piston 3 and slide plate 5 and piston 3'. With this gap 7 a communicating hole 8 extends through bulkhead 1, thereby offering communication between cylinder 2 and 2.

A suction hole 10 extends through side wall 9 of cylinder 2 on the'opposite side of slide plate 5 from communicating hole 8. An exhaust hole 11 extends through side wall 9 of cylinder 2' on the opposite side of slide plate 5' from communicating hole 8. Ignition plug 12 extends through side wall 9 into cylinder 2.

The operation of the rotary engine of the present invention will now be described. As shown in FIG. 4, fuel is induced through suction hole 10 into cylinder 2, and is supplied into cylinder 2' through communicating hole 8 upon rotation of piston 3 to its eccentric downward position. Since the volume of cylinder 2' is smaller than the volume of cylinder 2, the fuel is compressed as it passes into cylinder 2. As piston 3 reaches the upper surface of cylinder 2, communicating hole 8 is closed, and the compressed fuel in cylinder 2 is exploded by ignition plug 12. At this moment, the exhaust hole 11 is on the opposite side of slide plate 5 from communicating hole 8. Thus, the compressed fuel is not allowed to be exhausted. However, as piston 3' continues to rotate, communication of the exploded combustion gas is opened through exhaust hole 11. It will be apparent that as piston 3 moves downwardly, piston 3 moves upwardly, thereby forcing fuel through communicating hole 8. It will be further apparent that since suction hole 10 is on the opposite side of slide plate 5 from communicating hole 8, fuel induced from suction hole 10 will not be allowed to flow back through hole 10. Also, as fuel is supplied through suction hole 10, the piston 3 is eccentrically rotated to make the volume of cylinder 2 larger. This manifestly creates a vacuum whereby the fuel is automatically induced through hole 10 in the cylinder 2. It will furthermore be apparent that there will never by leakage through slide plate 5 or 5', since these plates move upwardly and downwardly in close contact with piston 3 and 3, respectively, due to springs 4' and 4", respec tively.

Accordingly, it will be apparent that the rotary engine of the present invention allows a very large output of energy to be produced relative to the size and simplicity of the engine structure. It will furthermore be apparent that the majority of the various parts of the rotary engine of the present invention need not be made and assembled with precision. For instance, the exact locations of suction hole 10, communicating hole 8 and exhaust hole 11 need not be precise. Furthermore, it will be apparent that pistons 3 and 3 need not be mounted eccentrically at precisely a phase of Rather, this phase relationship need merely be only apro im t I p Aiisof a is shown in FIG. 5, a roll 13 may be mounted on the lower ends of slide plates ,5 and 5', to thereby reduce friction with pistons 3 and 3'.

Additionally, as will be apparent with reference to FIGS. 6 and 7,pistons 3 and 3 merely slide with respect to crank shaft 4 and do not actually rotate with respect to the inner walls of cylinders 2 and 2. Specifically, assuming the point of contact of piston 3 at any given time with the inner wall of cylinder 2 to be P, it has been found that P abuts the in er wall of cylinder 2 only once while piston 3 cycles around cylinder 2. This manifestly reduces friction on the pistons.

Although a single embodiment of the invention has been described in detail, such description is intended to be illustrative only, and not restrictive, since many details of the construction of the invention may be altered or modified without departing from the spirit or scope thereof.

What is claimed is:

l. A roller piston type rotary engine comprising first and second cylinders of different volumes and separated by a bulkhead; a crank shaft mounted in said engine to extend transversely through and rotate in said cylinders; a first roller piston mounted eccentrically on said crank shaft in said first cylinder; a second roller piston having a volume different from said first roller piston mounted eccentrically on said crank shaft in said second cylinder; a first slide plate mounted to extend into said first cylinder radially in the direction of said crank shaft and tightly contact the outer wall of said first roller piston; a second slide plate mounted to extend into said second cylinder radially in the direction of said crank shaft and tightly contact the outer wall of said second roller piston; the line of contact between said first slide plate and said first roller piston being slightly offset from the line of contact between said second slide plate and said second roller piston, whereby a gap is formed between said lines of contact; a communicating hole between said cylinders through said bulkhead in the area of said gap; a section hole through said engine into said first cylinder on the sideof said first slide plate opposite said communicating hole; and an exhaust hole through said engine into said second cylinder on the side of said second slide plate opposite said communicating hole. I

2. A roller piston type rotary engine as claimed in claim 1, wherein the volume of said first cylinder is greater than the volume of said second cylinder, and the volume of said first roller piston is greater than the volume of said second roller piston.

3. A roller piston type rotary engine as claimed in claim 1, wherein said first roller piston is mounted eccentrically approximately 180 out of phase with said second roller piston.

4. A roller piston type rotary engine as claimed in claim 1, wherein said roller pistons are loosely mounted on said crankshaft whereby as said crankshaft rotates, said roller pistons do not rotate with respect to the inner surfaces of said cylinders. 

1. A roller piston type rotary engine comprising first and second cylinders of different volumes and separated by a bulkhead; a crank shaft mounted in said engine to extend transversely through and rotate in said cylinders; a first roller piston mounted eccentrically on said crank shaft in said first cylinder; a second roller piston having a volume different from said first roller piston mounted eccentrically on said crank shaft in said second cylinder; a first slide plate mounted to extend into said first cylinder radially in the direction of said crank shaft and tightly contact the outer wall of said first roller piston; a second slide plate mounted to extend into said second cylinder radially in the direction of said crank shaft and tightly contact the outer wall of said second roller piston; the line of contact between said first slide plate and said first roller piston being slightly offset from the line of contact between said second slide plate and said second roller piston, whereby a gap is formed between said lines of contact; a communicating hole between said cylinders through said bulkhead in the area of said gap; a section hole through said engine into said first cylinder on the side of said first slide plate opposite said communicating hole; and an exhaust hole through said engine into said second cylinder on the side of said second slide plate opposite said communicating hole.
 2. A roller piston type rotary engine as claimed in claim 1, wherein the volume of said first cylinder is greater than the volume of said second cylinder, and the volume of said first roller piston is greater than the volume of said second roller piston.
 3. A roller piston type rotary engine as claimed in claim 1, wherein said first roller piston is mounted eccentrically approximately 180* out of phase with said second roller piston.
 4. A roller piston type rotary engine as claimed in claim 1, wherein said roller pistons are loosely mounted on said crankshaft whereby as said crankshaft rotates, said roller pistons do not rotate with respect to the inner surfaces of said cylinders. 